This paper presents a novel optimal Motion Cueing Algorithm(MCA)to control the rotations of a Human Centrifuge(HC)and achieve the best simulation of a Space Craft(SC)motion.Relations of the specific forces sensed by a...This paper presents a novel optimal Motion Cueing Algorithm(MCA)to control the rotations of a Human Centrifuge(HC)and achieve the best simulation of a Space Craft(SC)motion.Relations of the specific forces sensed by astronauts of the SC and the HC have been derived and linearized.A Linear Quadratic Regulator(LQR)controller is implemented for the problem which tends to minimize the error between the two sensed specific forces as well as control input in a cost function.It results in control inputs of the HC to generate its sensed specific force as close as possible to the one in the SC.The algorithm is implemented for both linearized and nonlinear portions of a US space shuttle mission trajectory as a verification using MATLAB.In longitudinal direction,the proposed MCA,works well when the acceleration is less than 2 g in which the tracking error does not exceed 12%.In lateral direction the tracking is much better even in nonlinear region since the error remains less than 7%for tilting up to 50°.Finally,the effect of weight matrixes in the LQR cost function on overall weight and power of the HC motion system is discussed.展开更多
Motion cueing algorithm plays a key role in simulator motion reproduction and improves the realism of movement sensation by combining with the human vestibular system.It is well established that scaling&limiting s...Motion cueing algorithm plays a key role in simulator motion reproduction and improves the realism of movement sensation by combining with the human vestibular system.It is well established that scaling&limiting should be used to decrease the amplitude of the acceleration and angular velocity signals for making full use of limited workspace of motion platform.A novel nonlinear scaling method based on a third-order polynomial and back propagation(BP)neural networks for the motion cueing algorithm is proposed in this paper.The third-order polynomial method is applied to the low amplitude segment of the input signal to minimize the trigger delay of the sensation acceleration;in the high amplitude segment,the BP neural network is used to adaptively adjust the scaling factor of the input signal,to avoid washout displacement and angular displacement beyond the boundary of the workspace.The simulation experiment is verified in the longitudinal/pitch direction for flight simulator,and the result implies that the proposed method not only can overcome the problem of constant scaling parameter and improve motion platform workspace utilization,but also reduce the false cues during the motion simulation process.展开更多
Motion cueing algorithms(MCA)are often applied in the motion simulators.In this paper,a nonlinear optimal MCA,taking into account translational and rotational motions of a simulator within its physical limitation,is d...Motion cueing algorithms(MCA)are often applied in the motion simulators.In this paper,a nonlinear optimal MCA,taking into account translational and rotational motions of a simulator within its physical limitation,is designed for the motion platform aiming to minimize human’s perception error in order to provide a high degree of fidelity.Indeed,the movement sensation center of most MCA is placed at the center of the upper platform,which may cause a certain error.Pilot’s station should be paid full attention to in the MCA.Apart from this,the scaling and limiting module plays an important role in optimizing the motion platform workspace and reducing false cues during motion reproduction.It should be used along within the washout filter to decrease the amplitude of the translational and rotational motion signals uniformly across all frequencies through the MCA.A nonlinear scaling method is designed to accurately duplicate motions with high realistic behavior and use the platform more efficiently without violating its physical limitations.The simulation experiment is verified in the longitudinal/pitch direction for motion simulator.The result implies that the proposed method can not only overcome the problem of the workspace limitations in the simulator motion reproduction and improve the realism of movement sensation,but also reduce the false cues to improve dynamic fidelity during the motion simulation process.展开更多
The classical washout algorithm had fixed gains and manually constructed filters, so that it led to poor adaptability. Furthermore, it lost the sustained acceleration cues of high-and mid-frequency in cross-over(tilt-...The classical washout algorithm had fixed gains and manually constructed filters, so that it led to poor adaptability. Furthermore, it lost the sustained acceleration cues of high-and mid-frequency in cross-over(tilt-coordination) channel, and the acceleration of cross-over frequency was also limited by angular velocity limiter, so the false cues in flight simulation process were clearly perceived by pilots. The paper studied the characteristics of the classical washout algorithm and flight simulator motion platform, tried to redesign the source of cross-over acceleration channel and translation acceleration channel, and transferred the part of cross-over acceleration that was unsimulated sustained acceleration to translation acceleration channel. Comparisons were mainly made between classical washout algorithm and revised algorithm in a longitudinal/pitch direction. The evaluation was based on the implementation of human vestibular perception system. The results demonstrated that the revised algorithm could significantly reduce the phase lag, and improved the spikes tracking performance. Furthermore, sensory angular velocity and the error of sensory acceleration were strictly controlled within the threshold of human perception system, and the displacement was a little broader than the classical washout algorithm. Therefore, it was proved that the new algorithm could diminish the filters parameters and heighten the self-adaptability for the washout algorithm. In addition, the magnitude of false cues was remarkably reduced during flight simulator, and the workspace utilization of the motion platform was developed by "closed-loop" control system.展开更多
Thanks to the emerging integration of algorithms and simulators, recent Driving Simulators (DS) find enormous potential in applications like advanced driver-assistance devices, analysis of driver’s behaviours, resear...Thanks to the emerging integration of algorithms and simulators, recent Driving Simulators (DS) find enormous potential in applications like advanced driver-assistance devices, analysis of driver’s behaviours, research and development of new vehicles and even for entertainment purposes. Driving simulators have been developed to reduce the cost of field studies, allow more flexible control over circumstances and measurements, and safely present hazardous conditions. The major challenge in a driving simulator is to reproduce realistic motions within hardware constraints. Motion Cueing Algorithm (MCA) guarantees a realistic motion perception in the simulator. However, the complex nature of the human perception system makes MCA implementation challenging. The present research aims to improve the performance of driving simulators by proposing and implementing the MCA algorithm as a control problem. The approach is realized using an actual vehicle model integrated with a detailed model of the human vestibular system, which accurately reproduces the driver’s perception. These perception motion signals are compared with simulated ones. A 2-DOF stabilized platform model is used to test the results from the two proposed control strategies, Proportional Integrator and Derivative (PID) and Model Predictive Control (MPC).展开更多
Scar formation resulting from burns or severe trauma can significantly compromise the structural integrity of skin and lead to permanent loss of skin appendages,ultimately impairing its normal physiological function.A...Scar formation resulting from burns or severe trauma can significantly compromise the structural integrity of skin and lead to permanent loss of skin appendages,ultimately impairing its normal physiological function.Accumulating evidence underscores the potential of targeted modulation of mechanical cues to enhance skin regeneration,promoting scarless repair by influencing the extracellular microenvironment and driving the phenotypic transitions.The field of skin repair and skin appendage regeneration has witnessed remarkable advancements in the utilization of biomaterials with distinct physical properties.However,a comprehensive understanding of the underlying mechanisms remains somewhat elusive,limiting the broader application of these innovations.In this review,we present two promising biomaterial-based mechanical approaches aimed at bolstering the regenerative capacity of compromised skin.The first approach involves leveraging biomaterials with specific biophysical properties to create an optimal scarless environment that supports cellular activities essential for regeneration.The second approach centers on harnessing mechanical forces exerted by biomaterials to enhance cellular plasticity,facilitating efficient cellular reprogramming and,consequently,promoting the regeneration of skin appendages.In summary,the manipulation of mechanical cues using biomaterial-based strategies holds significant promise as a supplementary approach for achieving scarless wound healing,coupled with the restoration of multiple skin appendage functions.展开更多
BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of cor...BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.展开更多
Research on human motion prediction has made significant progress due to its importance in the development of various artificial intelligence applications.However,effectively capturing spatio-temporal features for smo...Research on human motion prediction has made significant progress due to its importance in the development of various artificial intelligence applications.However,effectively capturing spatio-temporal features for smoother and more precise human motion prediction remains a challenge.To address these issues,a robust human motion prediction method via integration of spatial and temporal cues(RISTC)has been proposed.This method captures sufficient spatio-temporal correlation of the observable sequence of human poses by utilizing the spatio-temporal mixed feature extractor(MFE).In multi-layer MFEs,the channel-graph united attention blocks extract the augmented spatial features of the human poses in the channel and spatial dimension.Additionally,multi-scale temporal blocks have been designed to effectively capture complicated and highly dynamic temporal information.Our experiments on the Human3.6M and Carnegie Mellon University motion capture(CMU Mocap)datasets show that the proposed network yields higher prediction accuracy than the state-of-the-art methods.展开更多
Objectives This study aimed to clarify the relationship between the content of proxy decision-making made by families of patients with malignant brain tumors regarding treatment policies and daily care and the cues le...Objectives This study aimed to clarify the relationship between the content of proxy decision-making made by families of patients with malignant brain tumors regarding treatment policies and daily care and the cues leading to those decisions.Methods Semi-structured personal interviews were used to collect data.Seven family members of patients with malignant brain tumors were selected to participate in the study by purposive sampling method from June to August 2022 in the Patient Family Association of Japan.Responses were content analyzed to explore the relationship between the content of decisions regarding“treatment policies”and“daily care”and the cues influencing those decisions.Semi-structured interviews were analyzed by using thematic analysis.Results The contents of proxy decisions regarding“treatment policies”included implementation,interruption,and termination of initial treatments,free medical treatments,use of respirators,and end-of-life sedation and included six cues:treatment policies suggested by the primary physician,information and knowledge about the disease and treatment obtained by the family from limited resources,perceived life threat from symptom worsening,words and reactions from the patient regarding treatment,patient’s personality and way of life inferred from their treatment preferences,family’s thoughts and values hoping for better treatment for the patient.Decisions for“daily care”included meal content and methods,excretion,mobility,maintaining cleanliness,rehabilitation,continuation or resignation from work,treatment settings(outpatient or inpatient),and ways to spend time outside and included seven cues:words and thoughts from the patient about their way of life,patient’s reactions and life history inferred from their preferred way of living,things the patient can do to maintain daily life and roles,awareness of the increasing inability to do things in daily life,family’s underlying thoughts and values about how to spend the remaining time,approval from family members regarding the care setting,advice from medical professionals on living at home.Conclusions For“treatment policies,”guidelines from medical professionals were a key cue,while for“daily care,”the small signs from the patients in their daily lives served as cues for proxy decision-making.This may be due to the lack of information available to families and the limited time available for discussion with the patient.Families of patients with malignant brain tumors repeatedly use multiple cues to make proxy decision-making under high uncertainty.Therefore,nurses supporting proxy decision-making should assess the family’s situation and provide cues that facilitate informed and confident decisions.展开更多
Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make contextappropriate behavioral decisions.However,in sexually dimorphic species,mal...Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make contextappropriate behavioral decisions.However,in sexually dimorphic species,males and females are expected to differ in the perceived costs and/orbenefts associated with predator avoidance decisions.Recent studies suggest that male Trinidadian guppies(Poecilia reticulata)show reducedor absent responses to acute personal information cues,placing them at greater risk of predation relative to females.Our goal here was totest the hypothesis that adult(reproductively active)male guppies rely on social information to limit potential costs associated with their lack ofresponse to risky personal cues.Adult male guppies were exposed to personal chemosensory cues(either conspecifc alarm cues(AC),a novelodor,or a water control)in the presence of a shoal of three females inside a holding container that allowed the transmission of visual but notchemical cues.At the same time,we exposed females to either risk from AC or no risk,resulting in the display of a range of female behavior,from calm to alarmed,available as social information for males.Alarmed females caused male fright activity to increase and male interest infemales to decrease,regardless of the personal cue treatment.These results indicate that male guppies rely more on female information regarding predation risk than their own personal information,probably to balance trade-offs between reproduction and predator avoidance.展开更多
This research aims to analyse the spatio-temporal changes of vegetation cover in coastal regions of Char Fasson and Galachipa Upazila, Bangladesh for a period of 30 years (1994-2024) based on Landsat satellite imagery...This research aims to analyse the spatio-temporal changes of vegetation cover in coastal regions of Char Fasson and Galachipa Upazila, Bangladesh for a period of 30 years (1994-2024) based on Landsat satellite imagery and NDVI. Through the evaluation of NDVI this paper classifies vegetation as no water/bare vegetation, slightly densed vegetation, moderately densed vegetation, and highly densed vegetation. The findings reveal significant fluctuations in vegetation cover: from 1994 to 2004, there has been an increase in vegetation density implying that afforestation has created more moderate and highly densed vegetation out of density vegetation. However, between 2004 and 2014, vegetation cover decreased because some cyclones, like Sidr and Aila, affected the coastal forest of Bangladesh. Other attempts to afforestation supported improved coverage from vegetation between 2014 and 2024. These findings provide clear evidence of the sustainable benefits of coastal afforestation in the reduction of coastal erosion and storm surges that affect vegetation and coasts. Knowledge gained in this research is highly useful to the environmental planners on recommendations for sustainable land uses and preservation to build up ecological stability in Bangladesh weak coastal areas.展开更多
植被碳利用率作为生物圈与大气圈碳循环的关键参数之一,对了解生态系统碳源和碳汇具有重要作用。本文基于MOD17A2H数据,采用Theil-Sen media趋势分析、空间插值以及偏相关分析法,分析2001~2020年西南地区植被碳利用率(Carbon Use Effici...植被碳利用率作为生物圈与大气圈碳循环的关键参数之一,对了解生态系统碳源和碳汇具有重要作用。本文基于MOD17A2H数据,采用Theil-Sen media趋势分析、空间插值以及偏相关分析法,分析2001~2020年西南地区植被碳利用率(Carbon Use Efficiency,CUE)时空分布格局及变化趋势,根据气象数据和数字高程模型(Digital Elevation Model,DEM)数据,重点研究了西南地区植被CUE对气候变化的响应。结果表明:(1)2001~2020年西南地区不同植被类型年内CUE整体呈上升—下降—再上升—再下降的变化特征,整体上各植被类型CUE呈下降趋势,下降速率依次为:灌木>森林>草地>农作物。(2)近20年西南地区植被CUE多年均值约为0.75,植被固碳能力较强,空间上表现出由南部和东北部向西北部递增的空间分布格局,趋势分析表明西南地区植被CUE整体表现为微弱下降趋势。(3)2001~2020年西南地区植被碳利用率与气温、降水以及日照时长均呈负相关关系,整体上西南地区植被CUE主要受气温和日照时长影响,其次为降水。展开更多
Printing three-dimensional(3D)scaffolds with suitable mechanical cues is an effective strategy for guiding tissue regeneration by inducing cell migration and growth.Nevertheless,many studies considered only one type o...Printing three-dimensional(3D)scaffolds with suitable mechanical cues is an effective strategy for guiding tissue regeneration by inducing cell migration and growth.Nevertheless,many studies considered only one type of cue for 3D tissue engineering scaffold fabrication,such as topological cues,which is insufficient.To realize durotaxis-and topotaxis-orchestrated guidance on cell migration,a 3D printed scaffold/hydrogel composite was fabricated in this study.The porous scaffold provided a topological cue(topotaxis),and the combined hydrogel provided a compliance cue(durotaxis).The results indicated that the thin fibers of the scaffold induced cell migration,and the larger pore size and directed fiber number of the scaffold led to more uniform cell orientation(topotaxis).Furthermore,when collagen was cured to cover the scaffold to result in a compliance change,the cells in the collagen still sensed the scaffold topological cue and migrated along it(durotaxis).Collagen also provides a living space and nutrition for cells,thereby significantly increasing their number.The effects of durotaxis and topotaxis synthesis provide a promising solution for tissue engineering scaffold applications.展开更多
Selection of a suitable habitat by animals before settlement is critical for their survival and reproduction.In silk-spinning arthropods like spider mites,denser webs offer protection from predation and serve as a dis...Selection of a suitable habitat by animals before settlement is critical for their survival and reproduction.In silk-spinning arthropods like spider mites,denser webs offer protection from predation and serve as a dispersal mode.Settling in habitats with the presence of conspecifics and silk webs can benefit the habitat-searching females.Silk and conspecifics usually coexist,but their distinct effects on female colonization have received little attention.In this study,we used a haplodiploid spider mite,Tetranychus ludeni Zacher(Acari:Tetranychidae),to examine the impact of conspecific cues,including cues from ovipositing conspecifics and silk,on habitat selection and subsequent reproductive performance of females.Results show that females significantly preferred habitats with cues from neighboring conspecifics and silk and neighboring conspecifics induced additive effect to that of silk on habitat selection.Conspecific cues did not boost female reproduction but facilitated females laying larger eggs that were more likely to be fertilized and to develop into daughters.When given a choice between silk-covered and clean habitats,females preferred silk-covered habitats,laid a similar number of eggs with similar size,but produced more daughters,suggesting that T.ludeni females can adjust the size threshold for fertilization in response to the current social environment.Knowledge of this study improves our understanding of spider mite habitat selection and post-settlement reproductive performance behaviors.展开更多
In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of pa...In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of parasite egg colors and markings in detection cues in hosts;however,studies focusing on the effects of egg size and quantity are relatively scarce and have mostly concentrated on the hosts of parasitic cowbirds.Here,we studied the egg recognition behaviors of a potential host of the Common Cuckoo(Cuculus canorus)—the Green-backed Tit(Parus monticolus),to determine:(1)whether the host uses the sizes of parasite eggs and/or the quantity contrast between parasite and host eggs as cues for recognition,(2)whether the host employs the template or discordant recognition mechanism for egg recognition,and(3)whether the size and quantity of parasite eggs affect the egg rejection modes of the hosts.The results indicate that Green-backed Tits did not use parasite egg size as a primary cue for egg recognition.We hypothesized that both visual and tactile detection might be involved in egg recognition by Green-backed Tits and suggest further studies after controlling for nest light conditions.Differences in egg quantity between parasites and hosts were not used as cues for egg recognition because the hosts employed the template mechanism rather than discordance to recognize parasite eggs.However,both the relative sizes and quantity of parasite and host eggs significantly affected the rejection modes of parasite eggs,and larger or more parasite eggs triggered higher probabilities of nest desertion in hosts.展开更多
Traditional building energy-saving research focuses on technical energy-saving and energy system energy-saving,while neglecting the study of personnel's energy-consumption behavior during the building operation ph...Traditional building energy-saving research focuses on technical energy-saving and energy system energy-saving,while neglecting the study of personnel's energy-consumption behavior during the building operation phase.In order to explore people's cognitive process of building energy-saving information,this paper focuses on the representativeness of the research on building energy-saving reminder information.The results are summarized,sorted out and analyzed.Based on relevant research at home and abroad,this paper reviews the conceptual connotation of building energy-saving reminder information,research methods and influencing factors on the recognition of building energy-saving reminder information.Finally,it summarizes the research landscape of the cognitive process of building energy-saving reminder information and analyzes the existing research.In light of the shortcomings,three major research directions are proposed in the future:integrating research scenarios and focusing on the interaction of multiple scenarios in the Chinese cultural environment;broadening research methods to explore the diversity and feasibility of emerging research methods;increasing the time span and improving experimental design dynamic and continuous.展开更多
The cashew stem girdler, Analeptes trifasciata Fabricius (Coleoptera: Cerambycidae), damages cashew by its girdling activities in the stem thereby causing huge economic losses. The stem girdler is managed through cult...The cashew stem girdler, Analeptes trifasciata Fabricius (Coleoptera: Cerambycidae), damages cashew by its girdling activities in the stem thereby causing huge economic losses. The stem girdler is managed through cultural practice of burning girdled stems and beetles, though this has drawbacks. The objective of this study was to explore the cues mediating attraction to the cashew host plant;hence the role of olfaction in host plant location by A. trifasciata underlying the semio-chemical option for controlling this insect pest. A diffusional Y-tube olfactometer was used to study the behavioural response of A. trifasciata, to freshly cut cashew stem and leaves odour sources. Methanol-extract of these plant tissues was subjected to the coupled gas chromatography-mass spectrometry (GC-MS) analysis. Y-tube olfactometric assays demonstrated that both sexes oriented towards and spent significantly more time in stem odour arm compared to the leaf odour arm in both male (male: t = 2.228, d.f = 11, P = 0.040) and female (t = 2.341, d.f = 11, P = 0.040). A combination of fatty acids, amino acids and carbohydrates were detected in cashew stems. Some of these fatty acids are attractants to other insect pests. It is suspected that these fatty acid blends may possibly be responsible for facilitating host plant location by both sexes. In conclusion, both sexes were independently and strongly attracted to the stem volatiles;this study opens the possibility of utilizing cashew stem volatiles as surveillance and control tools.展开更多
文摘This paper presents a novel optimal Motion Cueing Algorithm(MCA)to control the rotations of a Human Centrifuge(HC)and achieve the best simulation of a Space Craft(SC)motion.Relations of the specific forces sensed by astronauts of the SC and the HC have been derived and linearized.A Linear Quadratic Regulator(LQR)controller is implemented for the problem which tends to minimize the error between the two sensed specific forces as well as control input in a cost function.It results in control inputs of the HC to generate its sensed specific force as close as possible to the one in the SC.The algorithm is implemented for both linearized and nonlinear portions of a US space shuttle mission trajectory as a verification using MATLAB.In longitudinal direction,the proposed MCA,works well when the acceleration is less than 2 g in which the tracking error does not exceed 12%.In lateral direction the tracking is much better even in nonlinear region since the error remains less than 7%for tilting up to 50°.Finally,the effect of weight matrixes in the LQR cost function on overall weight and power of the HC motion system is discussed.
基金Wuhan Technical College of Communications Fund(Y2019006)Wuhan Technical College of Communications Innovation Team(CX2018A07)。
文摘Motion cueing algorithm plays a key role in simulator motion reproduction and improves the realism of movement sensation by combining with the human vestibular system.It is well established that scaling&limiting should be used to decrease the amplitude of the acceleration and angular velocity signals for making full use of limited workspace of motion platform.A novel nonlinear scaling method based on a third-order polynomial and back propagation(BP)neural networks for the motion cueing algorithm is proposed in this paper.The third-order polynomial method is applied to the low amplitude segment of the input signal to minimize the trigger delay of the sensation acceleration;in the high amplitude segment,the BP neural network is used to adaptively adjust the scaling factor of the input signal,to avoid washout displacement and angular displacement beyond the boundary of the workspace.The simulation experiment is verified in the longitudinal/pitch direction for flight simulator,and the result implies that the proposed method not only can overcome the problem of constant scaling parameter and improve motion platform workspace utilization,but also reduce the false cues during the motion simulation process.
基金Supported by Natural Science Foundation of Hubei Province(2019CFB693)Scientific Research Guiding Project of Education Department of Hubei Province(B2020418)。
文摘Motion cueing algorithms(MCA)are often applied in the motion simulators.In this paper,a nonlinear optimal MCA,taking into account translational and rotational motions of a simulator within its physical limitation,is designed for the motion platform aiming to minimize human’s perception error in order to provide a high degree of fidelity.Indeed,the movement sensation center of most MCA is placed at the center of the upper platform,which may cause a certain error.Pilot’s station should be paid full attention to in the MCA.Apart from this,the scaling and limiting module plays an important role in optimizing the motion platform workspace and reducing false cues during motion reproduction.It should be used along within the washout filter to decrease the amplitude of the translational and rotational motion signals uniformly across all frequencies through the MCA.A nonlinear scaling method is designed to accurately duplicate motions with high realistic behavior and use the platform more efficiently without violating its physical limitations.The simulation experiment is verified in the longitudinal/pitch direction for motion simulator.The result implies that the proposed method can not only overcome the problem of the workspace limitations in the simulator motion reproduction and improve the realism of movement sensation,but also reduce the false cues to improve dynamic fidelity during the motion simulation process.
基金Supported by Wuhan Technical College of Communications Fund(Q2018001)China Institute of Communications Education Fund(1602-248)Wuhan Technical College of Communications Innovation Team(CX2018A07)
文摘The classical washout algorithm had fixed gains and manually constructed filters, so that it led to poor adaptability. Furthermore, it lost the sustained acceleration cues of high-and mid-frequency in cross-over(tilt-coordination) channel, and the acceleration of cross-over frequency was also limited by angular velocity limiter, so the false cues in flight simulation process were clearly perceived by pilots. The paper studied the characteristics of the classical washout algorithm and flight simulator motion platform, tried to redesign the source of cross-over acceleration channel and translation acceleration channel, and transferred the part of cross-over acceleration that was unsimulated sustained acceleration to translation acceleration channel. Comparisons were mainly made between classical washout algorithm and revised algorithm in a longitudinal/pitch direction. The evaluation was based on the implementation of human vestibular perception system. The results demonstrated that the revised algorithm could significantly reduce the phase lag, and improved the spikes tracking performance. Furthermore, sensory angular velocity and the error of sensory acceleration were strictly controlled within the threshold of human perception system, and the displacement was a little broader than the classical washout algorithm. Therefore, it was proved that the new algorithm could diminish the filters parameters and heighten the self-adaptability for the washout algorithm. In addition, the magnitude of false cues was remarkably reduced during flight simulator, and the workspace utilization of the motion platform was developed by "closed-loop" control system.
基金the Warsaw University of Technology(WUT),grant No.504440200007Ali Soltani Sharif Abadi acknowledges support from WUT,grant No.504440200003.
文摘Thanks to the emerging integration of algorithms and simulators, recent Driving Simulators (DS) find enormous potential in applications like advanced driver-assistance devices, analysis of driver’s behaviours, research and development of new vehicles and even for entertainment purposes. Driving simulators have been developed to reduce the cost of field studies, allow more flexible control over circumstances and measurements, and safely present hazardous conditions. The major challenge in a driving simulator is to reproduce realistic motions within hardware constraints. Motion Cueing Algorithm (MCA) guarantees a realistic motion perception in the simulator. However, the complex nature of the human perception system makes MCA implementation challenging. The present research aims to improve the performance of driving simulators by proposing and implementing the MCA algorithm as a control problem. The approach is realized using an actual vehicle model integrated with a detailed model of the human vestibular system, which accurately reproduces the driver’s perception. These perception motion signals are compared with simulated ones. A 2-DOF stabilized platform model is used to test the results from the two proposed control strategies, Proportional Integrator and Derivative (PID) and Model Predictive Control (MPC).
基金supported in part by the National Nature Science Foundation of China(92268206,81830064)the CAMS Innovation Fund for Medical Sciences(CIFMS,2019-I2M-5-059)+4 种基金the Military Medical Research Projects(145AKJ260015000X,2022-JCJQ-ZB-09600)the Military Key Basic Research of Foundational Strengthening Program(2020-JCJQ-ZD-256-021)the Science Foundation of National Defense Science and Technology for Excellent Young(2022-JCJQ-ZQ-017)the Military Medical Research and Development Projects(AWS17J005,2019-126)the Specific Research Fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202317).
文摘Scar formation resulting from burns or severe trauma can significantly compromise the structural integrity of skin and lead to permanent loss of skin appendages,ultimately impairing its normal physiological function.Accumulating evidence underscores the potential of targeted modulation of mechanical cues to enhance skin regeneration,promoting scarless repair by influencing the extracellular microenvironment and driving the phenotypic transitions.The field of skin repair and skin appendage regeneration has witnessed remarkable advancements in the utilization of biomaterials with distinct physical properties.However,a comprehensive understanding of the underlying mechanisms remains somewhat elusive,limiting the broader application of these innovations.In this review,we present two promising biomaterial-based mechanical approaches aimed at bolstering the regenerative capacity of compromised skin.The first approach involves leveraging biomaterials with specific biophysical properties to create an optimal scarless environment that supports cellular activities essential for regeneration.The second approach centers on harnessing mechanical forces exerted by biomaterials to enhance cellular plasticity,facilitating efficient cellular reprogramming and,consequently,promoting the regeneration of skin appendages.In summary,the manipulation of mechanical cues using biomaterial-based strategies holds significant promise as a supplementary approach for achieving scarless wound healing,coupled with the restoration of multiple skin appendage functions.
文摘BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.
基金supported by the National Key R&D Program of China(No.2018YFB1305200)the Natural Science Foundation of Zhejiang Province(No.LGG21F030011)。
文摘Research on human motion prediction has made significant progress due to its importance in the development of various artificial intelligence applications.However,effectively capturing spatio-temporal features for smoother and more precise human motion prediction remains a challenge.To address these issues,a robust human motion prediction method via integration of spatial and temporal cues(RISTC)has been proposed.This method captures sufficient spatio-temporal correlation of the observable sequence of human poses by utilizing the spatio-temporal mixed feature extractor(MFE).In multi-layer MFEs,the channel-graph united attention blocks extract the augmented spatial features of the human poses in the channel and spatial dimension.Additionally,multi-scale temporal blocks have been designed to effectively capture complicated and highly dynamic temporal information.Our experiments on the Human3.6M and Carnegie Mellon University motion capture(CMU Mocap)datasets show that the proposed network yields higher prediction accuracy than the state-of-the-art methods.
文摘Objectives This study aimed to clarify the relationship between the content of proxy decision-making made by families of patients with malignant brain tumors regarding treatment policies and daily care and the cues leading to those decisions.Methods Semi-structured personal interviews were used to collect data.Seven family members of patients with malignant brain tumors were selected to participate in the study by purposive sampling method from June to August 2022 in the Patient Family Association of Japan.Responses were content analyzed to explore the relationship between the content of decisions regarding“treatment policies”and“daily care”and the cues influencing those decisions.Semi-structured interviews were analyzed by using thematic analysis.Results The contents of proxy decisions regarding“treatment policies”included implementation,interruption,and termination of initial treatments,free medical treatments,use of respirators,and end-of-life sedation and included six cues:treatment policies suggested by the primary physician,information and knowledge about the disease and treatment obtained by the family from limited resources,perceived life threat from symptom worsening,words and reactions from the patient regarding treatment,patient’s personality and way of life inferred from their treatment preferences,family’s thoughts and values hoping for better treatment for the patient.Decisions for“daily care”included meal content and methods,excretion,mobility,maintaining cleanliness,rehabilitation,continuation or resignation from work,treatment settings(outpatient or inpatient),and ways to spend time outside and included seven cues:words and thoughts from the patient about their way of life,patient’s reactions and life history inferred from their preferred way of living,things the patient can do to maintain daily life and roles,awareness of the increasing inability to do things in daily life,family’s underlying thoughts and values about how to spend the remaining time,approval from family members regarding the care setting,advice from medical professionals on living at home.Conclusions For“treatment policies,”guidelines from medical professionals were a key cue,while for“daily care,”the small signs from the patients in their daily lives served as cues for proxy decision-making.This may be due to the lack of information available to families and the limited time available for discussion with the patient.Families of patients with malignant brain tumors repeatedly use multiple cues to make proxy decision-making under high uncertainty.Therefore,nurses supporting proxy decision-making should assess the family’s situation and provide cues that facilitate informed and confident decisions.
基金supported by Concordia University and funded by the Natural Sciences and Engineering Research Council of Canada(Discovery Grant to G.E.B.,and an E.W.R.SteacieMemorial Fellowship to M.C.O.F.).
文摘Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make contextappropriate behavioral decisions.However,in sexually dimorphic species,males and females are expected to differ in the perceived costs and/orbenefts associated with predator avoidance decisions.Recent studies suggest that male Trinidadian guppies(Poecilia reticulata)show reducedor absent responses to acute personal information cues,placing them at greater risk of predation relative to females.Our goal here was totest the hypothesis that adult(reproductively active)male guppies rely on social information to limit potential costs associated with their lack ofresponse to risky personal cues.Adult male guppies were exposed to personal chemosensory cues(either conspecifc alarm cues(AC),a novelodor,or a water control)in the presence of a shoal of three females inside a holding container that allowed the transmission of visual but notchemical cues.At the same time,we exposed females to either risk from AC or no risk,resulting in the display of a range of female behavior,from calm to alarmed,available as social information for males.Alarmed females caused male fright activity to increase and male interest infemales to decrease,regardless of the personal cue treatment.These results indicate that male guppies rely more on female information regarding predation risk than their own personal information,probably to balance trade-offs between reproduction and predator avoidance.
文摘This research aims to analyse the spatio-temporal changes of vegetation cover in coastal regions of Char Fasson and Galachipa Upazila, Bangladesh for a period of 30 years (1994-2024) based on Landsat satellite imagery and NDVI. Through the evaluation of NDVI this paper classifies vegetation as no water/bare vegetation, slightly densed vegetation, moderately densed vegetation, and highly densed vegetation. The findings reveal significant fluctuations in vegetation cover: from 1994 to 2004, there has been an increase in vegetation density implying that afforestation has created more moderate and highly densed vegetation out of density vegetation. However, between 2004 and 2014, vegetation cover decreased because some cyclones, like Sidr and Aila, affected the coastal forest of Bangladesh. Other attempts to afforestation supported improved coverage from vegetation between 2014 and 2024. These findings provide clear evidence of the sustainable benefits of coastal afforestation in the reduction of coastal erosion and storm surges that affect vegetation and coasts. Knowledge gained in this research is highly useful to the environmental planners on recommendations for sustainable land uses and preservation to build up ecological stability in Bangladesh weak coastal areas.
基金supported by National Natural Science Foundation of China(Grant.No.52305558)Hubei Provincial Natural Science Foun-dation of China(Grant.Nos.2023AFB141,2023AFB807)+1 种基金Key Research and Development Plan of Zhejiang Province(Grant.No.2023C01169)Ezhou Industrial Technology Research Institute,Huazhong University of Science and Technology(Customizable Multi-nozzle 3D Bio-printing Technology&Equipment Project).
文摘Printing three-dimensional(3D)scaffolds with suitable mechanical cues is an effective strategy for guiding tissue regeneration by inducing cell migration and growth.Nevertheless,many studies considered only one type of cue for 3D tissue engineering scaffold fabrication,such as topological cues,which is insufficient.To realize durotaxis-and topotaxis-orchestrated guidance on cell migration,a 3D printed scaffold/hydrogel composite was fabricated in this study.The porous scaffold provided a topological cue(topotaxis),and the combined hydrogel provided a compliance cue(durotaxis).The results indicated that the thin fibers of the scaffold induced cell migration,and the larger pore size and directed fiber number of the scaffold led to more uniform cell orientation(topotaxis).Furthermore,when collagen was cured to cover the scaffold to result in a compliance change,the cells in the collagen still sensed the scaffold topological cue and migrated along it(durotaxis).Collagen also provides a living space and nutrition for cells,thereby significantly increasing their number.The effects of durotaxis and topotaxis synthesis provide a promising solution for tissue engineering scaffold applications.
基金jointly funded by Accelerating Higher Education Expansion and Development Project(AHEAD)launched by the Sri Lankan Government under the funds of the World BankMassey University,New Zealand.
文摘Selection of a suitable habitat by animals before settlement is critical for their survival and reproduction.In silk-spinning arthropods like spider mites,denser webs offer protection from predation and serve as a dispersal mode.Settling in habitats with the presence of conspecifics and silk webs can benefit the habitat-searching females.Silk and conspecifics usually coexist,but their distinct effects on female colonization have received little attention.In this study,we used a haplodiploid spider mite,Tetranychus ludeni Zacher(Acari:Tetranychidae),to examine the impact of conspecific cues,including cues from ovipositing conspecifics and silk,on habitat selection and subsequent reproductive performance of females.Results show that females significantly preferred habitats with cues from neighboring conspecifics and silk and neighboring conspecifics induced additive effect to that of silk on habitat selection.Conspecific cues did not boost female reproduction but facilitated females laying larger eggs that were more likely to be fertilized and to develop into daughters.When given a choice between silk-covered and clean habitats,females preferred silk-covered habitats,laid a similar number of eggs with similar size,but produced more daughters,suggesting that T.ludeni females can adjust the size threshold for fertilization in response to the current social environment.Knowledge of this study improves our understanding of spider mite habitat selection and post-settlement reproductive performance behaviors.
基金funded by the Education Department of Hainan Province(No.HnjgY,2022–12)the National Natural Science Foundation of China(No.32260127 to C.Y.)Doctoral Start-up Funds of China West Normal University(No.493002 to P.Y.).
文摘In the co-evolutionary system of avian brood parasitism,egg recognition and rejection are common and generally act as effective anti-parasitic adaptations by hosts.Accordingly,most studies have examined the role of parasite egg colors and markings in detection cues in hosts;however,studies focusing on the effects of egg size and quantity are relatively scarce and have mostly concentrated on the hosts of parasitic cowbirds.Here,we studied the egg recognition behaviors of a potential host of the Common Cuckoo(Cuculus canorus)—the Green-backed Tit(Parus monticolus),to determine:(1)whether the host uses the sizes of parasite eggs and/or the quantity contrast between parasite and host eggs as cues for recognition,(2)whether the host employs the template or discordant recognition mechanism for egg recognition,and(3)whether the size and quantity of parasite eggs affect the egg rejection modes of the hosts.The results indicate that Green-backed Tits did not use parasite egg size as a primary cue for egg recognition.We hypothesized that both visual and tactile detection might be involved in egg recognition by Green-backed Tits and suggest further studies after controlling for nest light conditions.Differences in egg quantity between parasites and hosts were not used as cues for egg recognition because the hosts employed the template mechanism rather than discordance to recognize parasite eggs.However,both the relative sizes and quantity of parasite and host eggs significantly affected the rejection modes of parasite eggs,and larger or more parasite eggs triggered higher probabilities of nest desertion in hosts.
基金supported by National Natural Science Foundation of China(Grant No.71872122).
文摘Traditional building energy-saving research focuses on technical energy-saving and energy system energy-saving,while neglecting the study of personnel's energy-consumption behavior during the building operation phase.In order to explore people's cognitive process of building energy-saving information,this paper focuses on the representativeness of the research on building energy-saving reminder information.The results are summarized,sorted out and analyzed.Based on relevant research at home and abroad,this paper reviews the conceptual connotation of building energy-saving reminder information,research methods and influencing factors on the recognition of building energy-saving reminder information.Finally,it summarizes the research landscape of the cognitive process of building energy-saving reminder information and analyzes the existing research.In light of the shortcomings,three major research directions are proposed in the future:integrating research scenarios and focusing on the interaction of multiple scenarios in the Chinese cultural environment;broadening research methods to explore the diversity and feasibility of emerging research methods;increasing the time span and improving experimental design dynamic and continuous.
文摘The cashew stem girdler, Analeptes trifasciata Fabricius (Coleoptera: Cerambycidae), damages cashew by its girdling activities in the stem thereby causing huge economic losses. The stem girdler is managed through cultural practice of burning girdled stems and beetles, though this has drawbacks. The objective of this study was to explore the cues mediating attraction to the cashew host plant;hence the role of olfaction in host plant location by A. trifasciata underlying the semio-chemical option for controlling this insect pest. A diffusional Y-tube olfactometer was used to study the behavioural response of A. trifasciata, to freshly cut cashew stem and leaves odour sources. Methanol-extract of these plant tissues was subjected to the coupled gas chromatography-mass spectrometry (GC-MS) analysis. Y-tube olfactometric assays demonstrated that both sexes oriented towards and spent significantly more time in stem odour arm compared to the leaf odour arm in both male (male: t = 2.228, d.f = 11, P = 0.040) and female (t = 2.341, d.f = 11, P = 0.040). A combination of fatty acids, amino acids and carbohydrates were detected in cashew stems. Some of these fatty acids are attractants to other insect pests. It is suspected that these fatty acid blends may possibly be responsible for facilitating host plant location by both sexes. In conclusion, both sexes were independently and strongly attracted to the stem volatiles;this study opens the possibility of utilizing cashew stem volatiles as surveillance and control tools.
